Hi Bob,
You've help out alot with the information you have posted here. In
fact, I'm waiting for your book to come out. I must tell you though
that in this post you mention trying Warren Gregorie's headsets. My
first headset was purchased from Gregorie and I would advise anyone
looking at these to stay clear. My headset only lasted 20 hours of
flight time. When I contacted Gregorie to return for warrenty I was
told "if your having problems with your headset, look elswhere". He do
not honor his warrenty. You may have had a different experience, but I
personnally will stay away from his products.
Lou